Get down to Carphonewarehouse or somewhere similar and ask to give it a try.
I find it just fine. You can turn the phone to 'landscape' and use the keyboard that way. Or if you really, really like the old phone keypad style of texting you can still use that. I would strongly recommend giving swiftkey a try. It works out common phrases and starts suggesting options for what your typing. You can even get reports on how much your productivity has increased.